Abstract:
This thesis describes the results of an investigation by means of X-ray diffraction powder photographs of the minerals from the pegmatites of southeastern Manitoba. These pegmatites are located in an area that is about 100 miles northeast of Winnipeg. Reference is made to all the minerals that have been reported from these pegmatites although the X-ray diffraction study did not include all these minerals because specimens of all of them were not available to the writer. Each mineral was photographed with a standard small (57.3 mm. diameter) powder camera, but when the complexity of the mineral warranted more detailed work a standard large (114.6 mm. diameter) powder camera was used. The main source of reference was the well-known A.S.T.M. X-ray Powder Data File. In this thesis the non-silicate minerals are classified according to the Seventh Edition of Dana's System of Mineralogy, Volume 1 and 2, and the silicates are classified according to Strunz in his Mineralogische Tabellen. Powder data are given for 29 minerals of which six have not previously been reported from this area, and eight have been identified more specifically than previously. The minerals which had not been reported earlier are: jamesonite from south of Shatford Lake, brazilianite (?) and "sarospatite" (illite-montmorillonite) from the Chemalloy mine at Bernic Lake, sicklerite from east of Bernic Lake, and uranophane-sklodowskite and vesuvianite from the Huron claim, south of the Winnipeg River. New localities for magnetite and pollucite are reported, these localities being the Huron claim south of the Winnipeg River and north of Maskwa Lake respectively. The minerals which have been identified more specifically are: triphylite-lithiophilite, heterosite-purpurite, muscovite and lithian muscovite (which include all the writer's specimens called lepidolite and zinnwaldite), topaz, epidote-clinozoisite (including some material called zoisite), maximum microcline and low albite. The other minerals for which powder data are given are: cassiterite, tantalite, wodginite, rhodochrosite, amblygonite, apatite, beryl, tourmaline, spodumene, chlorite, biotite, petalite, and quartz.
